It is common practice in the erection of high rise buildings to provide a means whereby concrete slabs, for example flooring slabs, can be penetrated by service lines or pipes. In high rise buildings particular requirements as regards fire safety and materials used are specified, however, the same fire rating level is not required in lower rise buildings. It is important, however, to ensure that the slabs of lower rise buildings are water sealed, for example, in bathroom areas.
A number of different methods have been proposed for penetrating slabs such as those disclosed in U.S. Pat. Nos. 2,694,847, 3,004,320, 2,234,784, 3,276,176 and 2,968,855. In the above patents a sleeve is secured to formwork where an aperture is to be provided and concrete applied about the sleeve which is then removed with the formwork leaving an aperture for the passage of service lines. In such arrangements it is necessary to fill the aperture about the service line which has been passed therethrough to ensure appropriate fire ratings are met. The underneath side of the aperture is often required to be patched with cement or the like which causes difficulties because proper support to the patch cannot be provided, so that in many cases paper, boards or other materials are used to close the aperture before pouring concrete from the top side. Often this results in the underside of the aperture having a jagged bottom edge making awkward the provision of an aesthetically pleasing patch. The above procedure also may result in poor water proofing and the loss of fire rating. Further in this method if jointing of the service line of say an elbow is required, such joints must be located externally of the formed slab.
Other forms of penetration units are shown in U.S. Pat. Nos. 4,261,598, 4,077,599, 3,933,336, 3,346,230, 4,619,471 , 4,159,099, 3,800,486, 4,623,170, 3,328,055 and 4,488,388. The units described in each of the above U.S. Patents have further disadvantages and are not suited to the present application. For example, U.S. Pat. No. 4,261,598 describes a coupling which enables the connection of pipes within a slab, however, such arrangements are not allowable in many situations. Similar comments apply to U.S. Pat. No. 3,328,055 wherein a threaded connector is embedded in concrete to penetrate a concrete slab and for enabling threaded interconnection within the slab to other pipe members. Other arrangement such as in U.S. Pat. No. 4,488,388 result in the placement of a pipe supporting clamp within a slab which serves to grip a pipe which is passed through the sleeve. Other penetration units described in the above U.S. Patents are not suited to use with relatively thin slabs and also do not enable easy coupling of a pipe or duct which is passed through the slab with other connection elements.
In high rise buildings where PVC pipe work is used for a service line or duct it is important to ensure that the pipes are closed off in the event of fire so that smoke, gases and flame cannot travel through the pipes between different floors of the building. At present, means used for penetrating slabs for the passage of service lines or pipes do not incorporate means for efficiently preventing the passage of gases and flames through the service lines or pipes between floors.